staging: comedi: daqboard2000: checkpatch.pl cleanup (else after return)

Fix these checkpatch.pl warnings:

WARNING: else is not generally useful after a break or return

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>